Evidence of ancient Martian lake seen

PARIS, Sept. 2 (UPI) -- A European space probe has spotted an ancient delta, an indication a Martian crater was once filled by a lake, astronomers say.

The European Space Agency Mars Express orbiter photographed the delta in the Eberswalde crater in the southern highlands of Mars, an ESA release said Friday.

The 40-mile diameter crater was formed more than 3.7 billion years ago when an asteroid hit the planet, astronomers said.

Though much of the crater was covered by subsequent impacts, a delta and its feeder channels are still visible, covering an area of 44 square miles.

This delta structure provides a clear indication water flowed across the surface of Mars in the planet's early history, the ESA said.